package com.firefly.mobile.app.util;
import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.Cipher;
  
/**  
 * RSA安全编码组件  
 *   
 */  
public abstract class RSACoder extends Coder {   
    public static final String KEY_ALGORITHM = "RSA";   
//    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";   
    public static final String SIGNATURE_ALGORITHM = "SHA1WithRSA";   
    
    private static final String PUBLIC_KEY = "RSAPublicKey";   
    private static final String PRIVATE_KEY = "RSAPrivateKey";   
  
    /**  
     * 用私钥对信息生成数字签名  
     *   
     * @param data  
     *            加密数据  
     * @param privateKey  
     *            私钥  
     *   
     * @return  
     * @throws Exception  
     */  
    public static String sign(byte[] data, String privateKey) throws Exception {   
        // 解密由base64编码的私钥   
        byte[] keyBytes = decryptBASE64(privateKey);   
  
        // 构造PKCS8EncodedKeySpec对象   
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);   
  
        // KEY_ALGORITHM 指定的加密算法   
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);   
  
        // 取私钥匙对象   
        PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);   
  
        // 用私钥对信息生成数字签名   
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);   
        signature.initSign(priKey);   
        signature.update(data);   
  
        return encryptBASE64(signature.sign());   
    }   
  
    /**  
     * 校验数字签名  
     *   
     * @param data  
     *            加密数据  
     * @param publicKey  
     *            公钥  
     * @param sign  
     *            数字签名  
     *   
     * @return 校验成功返回true 失败返回false  
     * @throws Exception  
     *   
     */  
    public static boolean verify(byte[] data, String publicKey, String sign)   
            throws Exception {   
  
        // 解密由base64编码的公钥   
        byte[] keyBytes = decryptBASE64(publicKey);   
  
        // 构造X509EncodedKeySpec对象   
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);   
  
        // KEY_ALGORITHM 指定的加密算法   
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);   
  
        // 取公钥匙对象   
        PublicKey pubKey = keyFactory.generatePublic(keySpec);   
  
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);   
        signature.initVerify(pubKey);   
        signature.update(data);   
  
        // 验证签名是否正常   
        return signature.verify(decryptBASE64(sign));   
    }   
  
    /**  
     * 解密<br>  
     * 用私钥解密  
     *   
     * @param data  
     * @param key  
     * @return  
     * @throws Exception  
     */  
    public static String decryptByPrivateKey(byte[] data, String key)   
            throws Exception {   
        // 对密钥解密   
        byte[] keyBytes = decryptBASE64(key);   
  
        // 取得私钥   
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);   
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);   
        Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);   
  
        // 对数据解密   
//        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); 
//        System.out.println(keyFactory.getAlgorithm());
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.DECRYPT_MODE, privateKey);   
        
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < data.length; i += 128) {
     	   byte[] doFinal = cipher.doFinal(ByteUtil.subarray(data, i, i + 128));
     	   System.out.println(doFinal.length);
     	   sb.append(new String(doFinal).trim());
        }
  
        return sb.toString();   
//        return new String(cipher.doFinal(data));  
    }   
  
    /**  
     * 解密<br>  
     * 用私钥解密  
     *   
     * @param data  
     * @param key  
     * @return  
     * @throws Exception  
     */  
    public static String decryptByPublicKey(byte[] data, String key)   
            throws Exception {   
        // 对密钥解密   
        byte[] keyBytes = decryptBASE64(key);   
  
        // 取得公钥   
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);   
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);   
        Key publicKey = keyFactory.generatePublic(x509KeySpec);   
  
        // 对数据解密   
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());   
        cipher.init(Cipher.DECRYPT_MODE, publicKey);   
  
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < data.length; i += 128) {
     	   byte[] doFinal = cipher.doFinal(ByteUtil.subarray(data, i, i + 128));
     	   sb.append(new String(doFinal));
        }
        
//        return cipher.doFinal(data);   
        return sb.toString();
    }   
  
    /**  
     * 加密<br>  
     * 用公钥加密  
     *   
     * @param data  
     * @param key  
     * @return  
     * @throws Exception  
     */  
    public static String encryptByPublicKey(byte[] data, String key)   
            throws Exception {   
        // 对公钥解密   
        byte[] keyBytes = decryptBASE64(key); 
  
        // 取得公钥   
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);   
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);   
        Key publicKey = keyFactory.generatePublic(x509KeySpec);   
  
        // 对数据加密   
//        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());   
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding"); 
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);   
        ByteArrayOutputStream writer = new ByteArrayOutputStream();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < data.length; i += 100) {
     	   byte[] doFinal = cipher.doFinal(ByteUtil.subarray(data, i, i + 100));
     	 writer.write(doFinal);
     	 sb.append(encryptBASE64(doFinal));
        }
        System.out.println("111111"+sb.toString());
        System.out.println("222222"+encryptBASE64(writer.toByteArray()));
//        return cipher.doFinal(data);   
        return encryptBASE64(writer.toByteArray());
//        return sb.toString();
    }   
  
    /**  
     * 加密<br>  
     * 用私钥加密  
     *   
     * @param data  
     * @param key  
     * @return  
     * @throws Exception  
     */  
    public static String encryptByPrivateKey(byte[] data, String key)   
            throws Exception {   
        // 对密钥解密   
        byte[] keyBytes = decryptBASE64(key);   
  
        // 取得私钥   
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);   
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);   
        Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);   
  
        // 对数据加密   
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());   
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);   
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < data.length; i += 117) {
        	   byte[] doFinal = cipher.doFinal(ByteUtil.subarray(data, i, i + 117));
        	  
        	   sb.append(ByteUtil.toHexInfo(doFinal, "", ""));
        }
        return sb.toString();   
//        return new String( ByteUtil.byte2hex(cipher.doFinal(data)));
    }   
    
//    public static String encryptByPrivateKey(byte[] data, String key)throws Exception {
//		// 对密钥解密
//		byte[] keyBytes = decryptBASE64(key);
//
//		// 取得私钥
//		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
//		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
//		RSAPrivateKey privateKey = (RSAPrivateKey) keyFactory
//				.generatePrivate(pkcs8KeySpec);
//
//		String result = new BigInteger(1, data).modPow(privateKey.getPrivateExponent(),
//				privateKey.getModulus()).toString(16);
//		System.out.println("rsa"+result);
//		return result;
//
//		// 对数据加密
//		// Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
//		// cipher.init(Cipher.ENCRYPT_MODE, privateKey);
//		//
//		// return cipher.doFinal(data);
//	}   
  
    /**  
     * 取得私钥  
     *   
     * @param keyMap  
     * @return  
     * @throws Exception  
     */  
    public static String getPrivateKey(Map<String, Object> keyMap)   
            throws Exception {   
        Key key = (Key) keyMap.get(PRIVATE_KEY);   
  
        return encryptBASE64(key.getEncoded());   
    }   
  
    /**  
     * 取得公钥  
     *   
     * @param keyMap  
     * @return  
     * @throws Exception  
     */  
    public static String getPublicKey(Map<String, Object> keyMap)   
            throws Exception {   
        Key key = (Key) keyMap.get(PUBLIC_KEY);   
  
        return encryptBASE64(key.getEncoded());   
    }   
  
    /**  
     * 初始化密钥  
     *   
     * @return  
     * @throws Exception  
     */  
    public static Map<String, Object> initKey() throws Exception {   
        KeyPairGenerator keyPairGen = KeyPairGenerator   
                .getInstance(KEY_ALGORITHM);   
        keyPairGen.initialize(1024);   
  
        KeyPair keyPair = keyPairGen.generateKeyPair();   
  
        // 公钥   
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();   
  
        // 私钥   
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();   
  
        Map<String, Object> keyMap = new HashMap<String, Object>(2);   
  
        keyMap.put(PUBLIC_KEY, publicKey);   
        keyMap.put(PRIVATE_KEY, privateKey);   
        return keyMap;   
    }   
    
    public static void main(String[] args) {
    	try {
			Map<String, Object> keyMap = RSACoder.initKey();   
			String  publicKey = RSACoder.getPublicKey(keyMap);   
			String  privateKey = RSACoder.getPrivateKey(keyMap);   
			System.err.println("公钥: \n\r" + publicKey);   
			System.err.println("私钥： \n\r" + privateKey);
		} catch (Exception e) {
			e.printStackTrace();
		}   
	}
}  


